|
|
|
|
Home>Products>Journal and Reviews>I.RE.Mo.S.>Latest issue
International Review on Modelling and Simulations - February 2010 - Papers
International Review on Modelling and Simulations - Papers
Vol. 3. n. 1, pp. 1-9
Abstract - In this
paper, an analytical space vector pulse width modulation (SVPWM) method
for Multi-level inverter fed induction motor is presented. This method
is based on SVPWM method for two-level inverter. As the number of level
increasing, the SVPWM method becomes more and more complex. An intrinsic
relationship between multi-level and two-level is proposed by using a
linear transformation technique. In this technique the switching time of
vectors for two-level inverter can be transformed in to multi-level
inverter. A novel classification of voltage vectors is proposed in this
paper to determine the switching sequence. This method can be extended
for any levels of inverter. The simulation is carried out up to the
eleven-level inverter fed induction motor and the results are presented
and analyzed. The results have been good agreement with the published
work.
Keywords: Multi-Level Inverter, SVPWM, Modulation Index, Induction Motor.
Vol. 3. n. 1, pp. 10-19
Abstract - The aim
of this paper seeks to optimize the characteristics of an hybrid linear
tubular stepping motor.
Keywords: Force, Multi-Objective Optimization, Criteria Selection, Optimization Variables, Constraints, Genetic Algorithm, Hybrid Structure.
Vol. 3. n. 1, pp. 20-26
Abstract - Due to of
its geometry, the Linear Induction Motor (LIM) has an end effects
phenomena causing weakening of the air gap flux and the thrust force. In
this work, we described the end effects of the motor by introducing
speed dependent scale factors to the magnetizing inductance and series
resistance in the d-axis equivalent circuit. Thrust force and flux
equations are therefore modified. Also, a field orientation control
scheme is developed taking into account the end effects. Starting from
this study, the problems of the secondary flux attenuation and the
primary currents variations, due to the end effects, are evaluated by
simulation. To get higher control performance, the control scheme with
the end effects compensation is applied. Indeed, the variations are
determined by a neuronal model characterized by a potentiality to
quantify these variations on all operation ranges of the machine. The
new approach of control has allowed compensating those effects by action
on the different regulators; this approach has proved its robustness
against end effects than the conventional vector control.
Keywords: Linear Induction Motor, Vector Control, End Effects, Compensation, Quantification.
Vol. 3. n. 1, pp. 27-32
Abstract - This paper presents of sliding mode control (SMC) of permanent magnet synchronous motor with a space vector modulation, the Sliding Mode Control is a control technique in AC drive systems to obtain high performance torque control, the permanent magnet synchronous motor is fed from three phase bridge inverter which is operated with space vector modulation (SVM) Technique. Among the various modulation strategies Space Vector Modulation Technique is the efficient one because it has better spectral performance and output voltage is more closed to sinusoidal. These techniques when applied for speed control of permanent magnet synchronous motor by Sliding Mode Control. The simulation results show the method is simple and has high precision of control, and the system has good characteristics in steady state and during transients with permanent magnet synchronous machine. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Lyapunov, PMSM, SMC, SVPWM.
Vol. 3. n. 1, pp. 33-37
Abstract - The exact analytical and numerical development requires taking into account the real current density. So, the aim of this investigation is to find a real current density which can be compared to a sinusoidal form via the minimization of the space harmonics. In this article we will look for the possibility of establishing the best current configurations of conductors placed inside slots and giving rise to the stator’s or rotor’s real equivalent current density form , based on generalized distribution function which has the nearest sinusoidal form and consequently the minimal space harmonics. Indeed, the latter possibility is obtained by increasing the slots number or by a special distribution of the conductors inside the slots. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Electrical Machines, Current Density, Harmonic Spaces.
Vol. 3. n. 1, pp. 38-47
Abstract - Fault
detection and diagnosis can effect system reliability and avoid
expensive maintenance. In a manufacturing process, a simple fault can
lead to environmental damage; in this way, one of the most commonly
applied fault detection method is the parameter estimation technique. In
this paper, fault detection of a synchronous generator is discussed.
Parameter estimation based on Levenberg Maquardt (LM) and Genetic
Algorithms (GAs) are explored to estimate multiple parameters of a
synchronous generator continuous-time model. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Fault Detection, Parameter Estimation, MHE, Genetic Algorithms, Synchronous Generator, LM Algorithm.
Vol. 3. n. 1, pp. 48-56
Abstract - The electrical supply network is often the seat of incidents which cause disturbances. When such a defect occurs, there is birth of significant non symmetry of voltage which can endanger the safety of the people and the deterioration of the existing installations in the electrical supply networks, if it is not quickly eliminated. Voltages unbalances, to which we were worried, come from the increasing installation, by the user, of loads known as fluctuating. It is thus advisable to stress that the quality of the electric power depends not only on the supplier but also on the end-user [1]. This work sticks to the control of a Permanent Magnet Synchronous Machine (PMSM) connected to an unbalanced network. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Unbalanced Grid, (PMSM), Symmetrical Components, (PLL), (PNH), (GC), (MC), DC Link, (PSRF), (NSRF).
Vol. 3. n. 1, pp. 57-63
Abstract - This paper deals with the subject-matter of teaching immaterial issues like power system dynamics where the phenomena and events are not sense-perceptible. The dynamics of the power system are recognized as analogous to the dynamics of a simple mechanical pendulum taken into account the well-known classical model for the synchronous machine. It is shown that even for more sophisticated models including flux decay and Automatic Voltage Regulator the mechanical device can be taken as an analogous, since provided some considerations about variation and control of the pendulum length using certain control laws. The resulting mathematical model represents a mechanical system that can be built for use in laboratory teaching of power system dynamics. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Electrical Power Systems, Dynamic Systems, Analog Model, Controllers, Stability, Simulation.
Vol. 3. n. 1, pp. 64-69
Abstract - Smart Grid is a topic that recently has attracted much attention. It is essential to develop a global strategy which will allow taking advantage of all the possible synergies to maximize the benefits of the implementation of new systems and improve their interoperability and interchangeability. Smart Grid technology research, development, and demonstration are urgently needed. The Smart Grid integrates new innovative tools and technologies from generation, transmission and distribution all the way to consumer appliances and equipment. To develop such a Smart Grid system that can provide advanced control and optimization, prediction, monitoring etc. it requires fast and dynamic algorithms that can learn system’s behavior; this is where computational intelligence comes in. In this paper we will concentrate on the Smart Grid concepts which consist of initiatives, technologies, characteristics, standards and solutions. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Smart Grid, Power System.
Vol. 3. n. 1, pp. 70-81
Abstract - Wind farms usually occupy large areas with high wind incidence, which often coincide with high keraunic levels and high relative soil resistivity (often in excess of several thousand Ωm in parts of southern Europe). Additionally, wind farms present complex mutually interconnected electrical system, consisted of wind turbines (with their earthing system), cable networks, transformer station (with earthing grid and high voltage apparatus) and high voltage overhead transmission network. High lightning strike incidence, combined with high soil resistivity, can have adverse effects on performance of individual wind turbines, other electrical equipment and on the wind farm as a whole. Whence, lightning induced overvoltage analysis of the involved electrical system, carried out with a sophisticated software package such as EMTP, is often regarded as the best approach in the course of the overvoltage protection selection for wind farms. Application of the appropriate model for each individual electrical system component, in the course of the lightning surge analysis, is a major topic of concern among researchers and engineers involved in this field. This paper will present propositions of components modelling as well as comparison of several possible models for each of the components of the associated electrical system of the wind farm. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Cables, EMTP, Grounding, Lightning, Model, Wind Farm.
Vol. 3. n. 1, pp. 82-89
Abstract - This paper describes dynamic modeling and simulation results of a small photovoltaic (PV)–fuel cell hybrid energy system. The dynamic behavior of the proposed hybrid system is tested under solar radiation and load demand conditions. The system consists of a PV, a proton exchange membrane fuel cell (PEMFC), ultra capacitors, an electrolyzer, and a power converter. The system is applicable for remote areas or isolated loads. The output of the PV is highly dependent on weather conditions, so the load is supplied from the PV with a fuel cell working in parallel. Excess PV energy when available is converted to hydrogen using an electrolyzer for later use in the fuel cell. FC power plant uses hydrogen and oxygen to convert chemical energy into electrical energy. Ultra-capacitor banks can be used for short-term energy storage due to their high cycling efficiency, convenience for charging/discharging, and additionally to meet the instantaneous load ripples/spikes. Besides, overloading fuel cell systems may cause gas starvation thus decreasing its performance and lifetime. As another feature, the load tracking delays and mismatches of the FCs should be compensated by an auxiliary system such as a battery or ultra capacitor bank. Power converter unit are proposed to generate AC voltage. PID type controllers are used to control the fuel cell system. MATLAB SIMULINK and Simpower Systems environment is used for the Simulation of this hybrid energy system. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Hybrid Energy Systems, Electrolyzer, Fuel Cell (Fc), Photovoltaic (Pv), Ultra Capacitor (Uc).
Vol. 3. n. 1, pp. 90-100
Abstract - In this paper, an efficient power system modelling technique by utilizing the concept of multi-terminal component is introduced and the modelling concept is applied to phase coordinated based fault analysis. The proposed technique is based on the separation of phases into groups and uses multi-terminal components to model three-phase power system. Using multi-terminal component and phase grouping technique, power system elements particularly lines and transformers can effectively be modelled. Consequently, the proposed technique is applied to three-phase and 9-bus test system in order to show how the proposed technique operates. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Power System Modelling, Phase Coordinates, Multi-Terminal Components, Fault Analysis.
Vol. 3. n. 1, pp. 101-107
Abstract - In this paper, the plasma arc welding is studied and stainless steel temperature field is gained in this process. The thermal effect of plasma arc that specially depends on the plasma and shielding gases type and temperature field of it in workpiece, is the main key of analysis and optimization of this process, from which the main goal of this paper has been defined. Numerical simulation of welding process in SIMPELC method and by ANSYS software for gaining the temperature field of stainless steel, the effect of parameter variation on temperature field and process optimization for different cases of plasma and shielding gases(Argon, Helium and mixture of them), are done. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Arc Plasma, Shielding Gas, Temperature Field, Stainless Steel, ANSYS-FSI.
Vol. 3. n. 1, pp. 108-115
Abstract - TIn this paper the Bond Graph modelling is applied to chemical reaction based processes with large industrial scale application. A specific thermochemical combustion process using pure combustible elements and a biochemical process were used in order to apply a specific approach adapted to physical system particularities – the Pseudo Bond Graph. By its large applicability, the approach represents an important tool in engineering design and operation for chemical based processes with industrial impact. Thus, the methane combustion presenting theoretical combustion characteristics was considered to model a termochemical process, and a baker’s yeast process, widely used in bioindustry, was considered as representative for a class of biochemical processes. Both processes are carried out into Continuous Stirred Tank Reactors. These models can be used as base for the development of chemical reactions with complex reaction kinetics. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Thermochemical Processes, Biochemical Processes, Bond Graphs, Modelling, Simulation.
Vol. 3. n. 1, pp. 116-123
Abstract - This paper summarizes computational results of three-dimensional laminar mixed convection air cooling of 10 cubic aluminium heated sources (blocks), simulating electronics components, which are mounted on a vertical channel wall. A three-dimensional, conjugate heat transfer model with appropriate boundary conditions is used in this work. The governing equations are solved by a finite volume method throughout the entire physical domain (solid and fluid). Calculations are made for a wide range of independent parameters (Gr, Re and H) in order to see theirs effects on the improvement of heat transfer inside the channel. The results are compared with the experimental data obtained with similar parameters. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Laminar, Mixed Convection, Cooling, Electronic Components, Channel.
Abstract - The characteristics of organic bulk heterojunction solar cells have been investigated and modelled. A composite of poly(2-methoxy-5-(39,79-dimethyloctyloxy)-1,4-phenylene-vinylene) (MDMO-PPV) and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) is used as photo-active material, sandwiched between a transparent Indium Tin Oxide (ITO)-electrode and an Al backside contact. This study aims to show the electrical effect of an extra interfacial layer of poly (3, 4- ethylenedioxythiophene)/(poly(styrenesulfonate)(PEDOT/PSS) on top of the ITO-electrode. Current-voltage characteristics of devices with and without this additional interfacial layer are compared and modeled by an equivalent electrical diagram. The simulation results clearly demonstrated that the current-voltage characteristics of the bulk heterojunction solar cell are affected by the presence of the PEDOT/PSS layer. Therefore, the solar cell is described, with sound accuracy, by single or two diode-equivalent models indicating the effects of the interfacial layer and of the thickness of the active layer on the photovoltaic performance of the studied devices. The theoretical results are in good agreement with the experimental observations. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Organic Solar Cell, Bulk Heterojunction, Current-Voltage Characteristic, Modelling, Simulation.
|
|
Please send any questions about this web site
to
info@praiseworthyprize.com
|
